Government-backed research has found Australia's nationwide contract tracing app unhelpful and inefficient for the country's COVID-19 pandemic response. 

A study funded by Australia's National Health and Medical Research Council and the New South Wales Ministry of Health evaluated the effectiveness and usefulness of COVIDSafe, a smartphone-based proximity tracing app introduced in April 2020. 

FINDINGS

Recently published in The Lancet Public Health journal this month, the study was done in NSW, the country's most populous state, and involved 619 confirmed locally acquired COVID-19 cases with over 25,300 close contacts identified through conventional contact tracing between 4 May and 4 November 2020. Semi-structured interviews with the state's public health staff were also conducted to assess the app's perceived usefulness.

The study identified three broad issues that seemed to make the app unhelpful for COVID-19 contact tracing in NSW:

• Lower-than-expected uptake among the at-risk population; 

• Poor diagnostic performance; and

• Low perceived usefulness by public health staff. 

Among positive cases, more than one in five or 137 people were using the COVIDSafe app. Only 79 people were considered their close contacts, giving the app a positive predictive value of 39%. Its estimated sensitivity, meanwhile, is at 15% as only 35 out of 236 identified close contacts were detected by the app. Additionally, the app spotted 17 more close contacts who were not identified by conventional contact tracing.

Meanwhile, the overwhelming response from the interviews was that COVIDSafe was not useful in contact tracing. Aside from its cumbersome interface, some health staff needed substantial assistance to access and interpret data, causing delays in the rollout and in notifying close contacts. The app, said the interviewees, did not shorten the timeframe for detecting close contacts. Moreover, they noted a discrepancy between iPhone and Android devices' ability to detect contacts and the poor ability to register contacts while phones are locked.

WHY IT MATTERS

Per the researchers, this is the first such study that looked into the potential benefits of digital contact tracing apps to COVID-19 public health response.

It concluded that the COVIDSafe app was "not sufficiently effective to make a meaningful contribution to COVID-19 contact tracing" in NSW due to the low app uptake, poor diagnostic performance, and difficulties for public health staff. 

Considering the high costs of operating such a digital tool, the study suggests integrating effective evaluations into the implementation of proximity contact tracing systems to justify investments. A government record showed that the estimated cost of developing and running COVIDSafe was at A$6.75 million ($4.7 million) with monthly maintenance costs of about A$100,000 ($70,000). The study also suggests using real-world piloting and user inputs post-implementation to ensure "added value" of digital tracing technology for public health.

THE LARGER TREND

There was a similar review of the COVIDSafe app which covered the March-November 2020 period. Done by consulting firm Abt Associates, the independent study also found the app unhelpful for contact tracing while putting more strain on already overworked health workers. 

While the federal government's review of the app admitted that the app had been "rarely" used due to relatively low COVID-19 cases recorded between May 2020 and May 2021, it still regarded the app as an "important addition" to the suite of tools that complements conventional contact tracing efforts.